Some current alarm systems monitor the Tip and Ring signals of a phone circuit in order to detect if the phone line to a home or commercial building has been disconnected. Typically, a 48VDC voltage level between the Tip and Ring lines is monitored by the alarm system. When, however, this voltage is removed, the alarm system will activate. In legacy telephone systems, this voltage is provided by a Central Office. In many new systems, though, an Optical Network Terminal (“ONT”) and/or a Multimedia Terminal Adapter (“MTA”) that provides this voltage are generally mounted locally, such as on the side of a home or in the home itself. Unfortunately, whenever a reset is required during an upgrade for such a system, an alarm is falsely activated since the power to the Subscriber Line Interface Circuit is interrupted.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of various embodiments of the present invention. Also, common and well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention.